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Radioactive Seed Localization (RSL)

As the technology behind screening mammograms becomes more refined, we are able to detect a greater number of breast abnormalities and cancers before they can be felt with a physical exam. While this allows us to catch problems earlier than ever, it also makes the affected tissue more challenging to precisely locate and remove.

The standard method is the wire-localization procedure (WLP). During this procedure, the radiologist places a guide-wire into the area of concern using mammography. The surgeon then removes the tissue surrounding the guide-wire and sends it to the laboratory for analysis.

While WLP is very useful, it also presents several challenges, especially with regard to accuracy. Radioactive seed localization (RSL) offers a new alternative. With this procedure, a radiologist uses mammography to place a very low-energy radioactive seed into the abnormal tissue or tumor. During the surgery, the surgeon uses a handheld Geiger counter (a device that detects radioactivity) to more precisely identify the location of the tumor. The Geiger counter also allows the surgeon to obtain a three dimensional view of the tumor’s location.

 

How RSL Works

You will have an appointment at Baystate Medical Center up to a week prior to your surgery for the implantation of the seed. A radiologist who has been specially trained in this procedure performs the seed implantation, assisted by a mammography technologist.

The seed placement procedure can often be performed with minimal or no discomfort. The radiologist will inject a local anesthetic to numb the area before starting the procedure. The local anesthetic may cause a brief burning sensation before the area becomes numb. Since mammography is used to place the seed, you will feel pressure from the paddles.

The seed (called Iodine 125 or I-125) is of very low energy, and its placement is not considered to be dangerous to you. Once the seed is removed with the breast tissue, all of the radioactivity is eliminated from your body.

 

Why Physicians Use RSL

RSL provides increased accuracy over WLP. With RSL, the surgeon knows the precise location of the tumor and can more accurately plan the surgical incision. This also reduces the length of the surgery. In addition, studies show that RSL reduces the need to have a second surgery due to incomplete removal of the abnormal tissue.

 

Benefits & Risks

RSL offers multiple benefits over WLP. The surgeon can implant the seed up to a week before the surgery, thereby making the scheduling process easier, reducing the wait time for patients, and shortening the time spent in the hospital.

More importantly, RSL provides increased accuracy over WLP. With RSL, the surgeon knows the precise location of the tumor and can more accurately plan the surgical incision. This also reduces the length of the surgery. In addition, studies show that RSL reduces the need to have a second surgery due to incomplete removal of the abnormal tissue.

The only way to remove a seed implanted in your breast is with surgery. You must not have a seed placed unless you are committed to undergoing surgery to remove it.

While the seed is implanted, people and objects around you are not at risk for radiation. However, to ensure the utmost safety, we recommend that you not allow children to sit on your lap while the seed is in place. We also recommend if you are nursing/lactating that you not breastfeed with the seed in place.

If you are pregnant, there is likely little risk to the fetus since the seed uses extremely low energy radiation. Since it is best to avoid any radiation exposure to the fetus, however, you must inform your surgeon of the pregnancy. We will then schedule you for the wire-localization procedure and will not use the radioactive seed.